The Urutau

The Urutau Features

The Urutau stands out with its bullpup design, prioritizing compactness while maintaining the performance of a 9mm carbine. This layout places the action behind the trigger, resulting in a shorter overall firearm that's easier to maneuver.

Key highlights include:

• Customizable Components: Alternative files like the left-handed bolt carrier housing with adhesive retention ribs for enhanced durability.
• Ventilation Design: A 3mm hole at the rear of the bolt carrier housing for improved assembly ventilation.
• Barrel Versatility: Notes on a 10"/250mm barrel length option included in the ECM document for tailored builds.

Special attention has been given to troubleshooting, with updates addressing issues like feeding failures through guide rod channel reaming and warnings about overlength firing pins. This design evolves with community feedback, ensuring a practical and user-friendly experience for builders.

Difficulty & Build Time

• Skill Level: Intermediate
• Estimated Build Time: 2-3 days
• Required Experience: Familiarity with 3D printing, firearm assembly, and basic troubleshooting skills

Hardware and Tools Required

Required Hardware

• 9mm AR9 barrels (note warnings about super/enhanced/extended feed cones)
• Stainless steel or other suitable material for boring & chambering rod
• Standard firearm components for fire control group testing
• Adhesive for retention ribs on alternative bolt carrier housing

Recommended Tools

• 3D printer capable of handling recommended materials
• Reaming tools for guide rod channel troubleshooting
• Basic firearm assembly tools for lower assembly steps
• Testing equipment for light primer strikes and loading verification

The Urutau Parts

The Urutau download includes a comprehensive set of STL files for printing the core components of this 9mm bullpup carbine. Key parts like the bolt carrier housing come with specific recommendations, such as limiting maximum volumetric speed during printing to ensure structural integrity. Alternative files, like the left-handed bolt carrier housing with adhesive retention ribs, offer customization options for unique builds.

For optimal results, print using durable materials suited for mechanical stress, with detailed assembly steps outlined in the provided documentation. Special considerations, such as channel reaming notes in step 16 and fire control group testing in step 28 of the lower assembly, are crucial for a successful build. Refer to the build instructions PDF at Urutau Documentation for a step-by-step guide.

Printer Compatibility & Settings

The Urutau files are compatible with most mid-range to high-end 3D printers capable of handling detailed and durable prints. Recommended materials include PETG or ABS for their strength and heat resistance, essential for firearm components. PLA is not advised due to its lower durability under stress.

Print settings should prioritize strength over speed, with a focus on limiting volumetric speed for critical parts like the bolt carrier housing as noted in the changelog. Ensure proper ventilation during printing, especially for parts with added ventilation holes. A well-calibrated printer with a heated bed is ideal for achieving the precision required for functional components.

Conclusion

The Urutau 9mm bullpup carbine is a groundbreaking project for 3D printing and firearms enthusiasts, blending compact design with powerful performance. With detailed documentation and community support at thegatalog.com, builders can tackle this intermediate-level project with confidence. Check back for updates and dive into the build instructions to start crafting your own Urutau today!